Do I have ADHD or ADD?

I am 13 years old, and I think I may have ADD/ADHD. I have been on different websites, and I seem to have these certain symptons that link to ADD/ADHD.

Very clumsy/accident prone I have great grades if I like a subject, but bad grades in subjects I find boring I have trouble concentrating on books if they are uninteresting or difficult to read I do a lot of things without thinking about what could happen/who I could hurt When Im sitting down I tend to fidget a lot. I often leave what I am doing because a sudden thought comes over and then I start thinking about it. I am very easily distracted. I am always walking around my bedroom, and sometimes I walk downstairs for no reason and then back up again. I find it hard to wait my turn. Impatient. I daydream. A lot. At school, during homework, when eating, when walking, when in the car, when on the computer. All the time. I have a short temper, and get irritable at things I easily become upset. I am very disorganized. RESTLESS! I usually have to be moving around to think. Enthuastic beginnings but poor endings with some things. I worry needlessly and endlessly In tests I find myself not knowing answers that I have been taught. I forget things like whether we had homework, and sometimes birthdays because im so interested in what Im doing. I have a lot of diffuculty sleeping because I have too many thoughts. I have diffuculty in waking, and end up usually going back to sleep again. My performance/schoolwork deteriotes when im under pressure.

Sooo … quite a lot, hey? I do think I have it, and now Im worrying and thinking about it all the time. I dont think my friends or family really know anything about it though, although they know that Im very hyper and can be silly at times. They probably dont even know what ADD/ADHD IS. I mean, I didnt a week ago.

So do you think I have it or not? And what should I do? Please help :P Or you could just leave me to worry about it …